What is respiratory syncytial virus (RSV)?

Respiratory syncytial (sin-SISH-uhl) virus (RSV) is a respiratory virus that causes mild, cold-like symptoms in older children and adults, but it can be serious in babies and young children. It's the most common cause of lower respiratory tract infections in young children.

Most children are infected with RSV sooner or later, usually at least once before age 2. In the United States, nearly 60,000 children younger than 5 are hospitalized with RSV each year, and most who are hospitalized are younger than 6 months old. Outbreaks of RSV are most common during peak cold season, which lasts from November to April.

How does respiratory syncytial virus spread?

RSV spreads easily through droplets in the air or from touching a contaminated surface. For example, a child can pick up RSV when an infected person sneezes or coughs nearby, or when a child touches a contaminated surface or toy then put his fingers in or near his mouth, nose, or eyes.

The virus can live on hard surfaces (such as doorknobs, countertops, and toys) for many hours, and on soft surfaces, such as hands or tissues for a shorter period of time.

Can respiratory syncytial virus lead to a more serious infection?

Yes. Although most children recover without any complications, some are more prone to develop a serious infection from RSV, which may require treatment in the hospital. Children at the highest risk include:

Premature babies

Children younger than 2 years old with congenital heart or chronic lung disease

Children with a weakened immune system

But in most cases, even when the infection is serious and children need extra care, they're in the hospital for only a few days and usually recover completely within two weeks.

What serious infections does respiratory syncytial virus cause?

In children, RSV is the most common cause of two lung disorders: bronchiolitis, which blocks air flow by making the small airways in the lungs swell and fill with mucus, and pneumonia, an infection and inflammation of the lungs.

At least a quarter of children have signs of bronchiolitis or pneumonia when exposed to RSV for the first time.

When should I call a doctor if my child has respiratory syncytial virus?

Call the doctor if your child has signs of a cold and:

Is younger than 3 months old

Was premature

Has lung or heart problems

Has a weakened immune system

Babies who are at least 3 months old and otherwise healthy don't need to see a doctor just to get a definite RSV diagnosis. But seek immediate medical attention if you suspect your child of any age could have RSV and also has one of these symptoms:

Labored or fast breathing

Excessive wheezing

A worsening cough

Thick yellow, green, or gray nasal mucus

Extreme fatigue

Gray or blue skin

High fever (100.4 or higher for babies younger than 3 months old)

How is respiratory syncytial virus diagnosed?

Your child's doctor can diagnose RSV during an office visit after doing a physical exam and a rapid RSV test, which can give the result in about 10 minutes. If a rapid RSV test isn't an option, the doctor can send a mucus sample from your child's nose or upper respiratory tract to a lab.

Your child's doctor may also use a pulse oximeter to test the level of oxygen in your child's blood (with a sensor painlessly attached to a finger or toe) to make sure that your child is getting enough oxygen.

What is the treatment for respiratory syncytial virus?

Mild symptoms may simply go away on their own in a week or two. But if your child has a serious infection caused by RSV, it's possible that he will need to be admitted to the hospital for oxygen treatments, IV fluids, and frequent nasal suctioning.

Some children may develop pneumonia as a complication of RSV. If this happens, your child will most likely get antibiotics to treat the bacterial infection. (Antibiotics won't work to treat RSV on its own because it's a virus.)

How can I make my child with respiratory syncytial virus comfortable?

Like the common cold, there's no cure for RSV, but you can take steps to keep your child comfortable:

Offer your child plenty of fluids to keep him well hydrated. If he's breastfeeding, nurse him as often as he'll eat.

Put a few drops of saline solution into his nose to loosen any mucus, then use a bulb syringe or nasal aspirator to suction it out. You can buy nasal saline solution over the counter at the drugstore.

Use a cool-mist vaporizer to moisten your child's airways, which makes it easier to breathe. Follow the manufacturer's directions for keeping it clean because it can spread germs through the air when it's dirty.

Keep your child away from cigarette smoke, fresh paint, wood smoke, or any other irritating fumes, which can make breathing more difficult. Exposure to tobacco smoke makes a serious bout of RSV or another respiratory virus more likely.

If your baby is younger than 3 months old, check with his doctor to see if it's okay to give him infants' acetaminophen to relieve discomfort. Once he's at least 6 months old, you can give him the proper dose of children's ibuprofen or acetaminophen.

Don't give your child an over-the-counter cold remedy unless the doctor says to. These remedies may seem to work in the short run, but they can make the problem worse and have serious side effects.

How can I prevent respiratory syncytial virus in my child?

These precautions are especially important if your child is at risk for a serious RSV infection:

Wash your hands and your child's hands often. Explain to your child's caregivers why this is important, and make sure they're conscientious about doing it too. At home, ask all visitors to wash their hands before handling your baby.

Avoid crowds and people who are ill.

If possible, keep your high-risk child home from daycare during RSV season (usually November to April, with a peak in January and February). Children at highest risk include infants, preemies, and children with a weakened immune system or heart or lung problems.

Beginning at age 6 months, make sure your child gets a flu shot every year in the fall or early winter.

If your child is at high risk, the doctor may prescribe palivizumab, a monthly injection given in the fall, winter, and spring months to help prevent RSV.

Is respiratory syncytial virus a serious concern for older kids or adults?

RSV isn't as much of a health concern for school-age children and adults. Although RSV can be serious, even fatal (especially in the elderly), most older children and adults with RSV simply have an upper respiratory infection characterized by a cough. Their immune systems are stronger, and their airways are bigger and less likely to become dangerously obstructed by inflammation.

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